Process for breaking petroleum emulsions



Patented Jan. 27, 1953 PROCESS FORBREAKING PETROLEUM ,EMULSIONS Melvin De .Groote, University City, Mo., assignor to .Petrolite Corporation, a corporation ofpela- No Drawing. Application Decemb er :14, 5195!), Serial No. 200 864 This invention relates to petroleum emulsions of the water-in-oil type "that are commonly re.-

ferred to-as flout oil, "roily,o;il, emulsified oil, etc. and'which comprise fine droplets of natural: ly-o ccuring waters or ,brines dispersed in a more or less permanentstate-{throughout the oil which constitutes the continuousphase of the emulsion.

One object of my invention is to provide a novel process for breaking or-resolvingemulsions of the kind referred to.

Another object of 'my invention is .to provide an economical and rapid process for separating emulsions which have been prepared under controlled conditionsfrommineraloil, such as crude oil and relatively soft waters or weak brines. Controlled .emulsification and subsequent demulsification under the conditions just mentioned, are of significant value in removing impurities particularly inorganic salts from pipeline oil.

Demulsification ascontemplated in the present application includes thepreventive step of commingling the demulsifier withthe aqueous ,component which would or might subsequently become either phaseof the emulsion, in absenceof such precautionary measure. Similarly, such demulsifier may be mixed with the hydrocarbon component.

The idemulsifying agent employed in the pres.- ent process is a 'fractionalester obtained from a polycarboxy acid anda diol obtained by the oxypropylation of a dihydroxy ether of glycerol. This glycerol ether is obtained by reacting one mole .of diethylene glycol monobutyl ether,-

C I-IsOCI-I2CH2OCHzCH2OH, with one mole of glycid, or any comparable procedure which produces the same compound or equivalent isomer thereof. Diethylene glycol monobutyl ether canbe prepared in any suitable manner and can be purchased under the particular designation of butyl Carbitol. My preference is to treat the glycerol ether of diethylene glycol monobutyl ether with sufficient propylene oxide so that the resulting product is not completely Watersoluble, i. e., is at least emulsifiable .or insoluble in Water, and also so the product is no longer completely insoluble in ,kerosene, i. e., tends to disperse ;or is soluble in kerosene. Needless to say, the upper molecular weight subsequently described involves products which are completely water-insoluble and completely kerosene-soluble as .difierentiated from dispersibility or emulsifiability. It is to be noted that the original glycol itself, i. e., diethylene glycol monobutyl ether, and also the dihydroxy compound obtained by reaction with glycerol ,monochlorohydrin or glycide is Water-soluble. Similarly the initial compounds, i. e., either the monohydroxylated compoundor the dihydroxylated compound prior Claims. (01. 352-340) 2 to .oxy ltq l ion is ker s rinsolu lc 1. th h et appendedclaim re en e .t the product being watereinsoluble means lack of solub' i' y either by being only dispersible, emulsifiablelni rapidly settling ,out, in layers, or for lthatnmat r completely insoluble in the, usual ,sense. intention is to differentiate .f,roman or 'ary soluble substance. Similarly c erence in theu claims to being at least kerosene-dispersiblQ m a a th Pr duc wi l at leas idi n t erp emulsiiy in ,kerosenelor may he ,ccmpl tely. sol:

uble in kerosene to give a clear, transparent,

homogeneoussolution.

As stat d e. monlirdri a cohol ha t i9 nroczno oa oicaneomn with the proviso that and ,n represent whole nu ber hich .addedrto cther equala umya y:

ing from 15 to 80,.andthe acidic ester obtainedby :gactlQnOf the polycarbony acid maybe indicated.

0 HooomngwoanmoR'owamom mooomw in which the characters have their previous significance, and n" is a ,whql egnumber not over 2 and R is the radical of the polycarboxy radical coon ' ('QQQHQP" and :preferably free from any radicals. having more than .8 uninterrupted carbon (atomsin -a single group, and with rtheifurther proviso that the parent diol prior .to .esterificationbe prefer; ably .waterdnsoluble or ,water-idispersible, and kerosene-soluble .or kerosene-dispersible.

Attention is directed-to the ,acor-pending-rapeplication .of ,C. Mu-Blair, .Jr., Serial No; 7,0;81-1, filed January. 113, 194 9,.-now;Batent 2,562,878, granted August ,7, 1951,,in which there aside: scribed, among other things, a procession-break: ing petroleumemulsions. of the water-imoilrtype characterized :by subjecting the emulsion. to the action of an esterification product of a .dicarbox-ylic acid and-a polyalkylene glycol in which the ratio of equivalentsof polybasic acid-:t0

equivalents of polyalkylene glycol is in the range of 0.5 to 2.0, in which the alkylene group has from 2 to 3 carbon atoms, and in which the molecular weight of the product is between 1,500 to 4,000.

Similarly, there have been used esters of dicarboxy acids and polypropylene glycols in which 2 moles of the dicarboxy acid ester have been reacted with one mole of a polypropylene glycol having a molecular weight, for example, of 2,000 so as to form an acidic fractional ester. Subsequent examination of what is said herein in comparison with the previous example as well as the hereto appended claims will show the line of delineation between such somewhat comparable compounds. Of greater significance, however, is What is said subsequently in regard to the structure of the parent diol as compared to polypropylene glycols Whose molecular weights may vary from 1,000 to 2,000.

For convenience, what is said hereinafter will be divided into six parts:

Part 1 will be concerned with the preparation of the diol by reacting diethylene glycol monobutyl ether with glycide or its equivalent;

Part 2 will be concerned with the oxypropylation of the diol obtained in the manner previously described in Part 1;

Part 3 will be concerned with the preparation of esters from the aforementioned oxypropylation derivatives;

Part 4 will be concerned with the structure of the herein described diols and their significance in light of what is said subsequently;

Part 5 will be concerned with the use of the products herein described as demulsifiers for breaking water-in-oil emulsions; and

Part 6 will be concerned with certain derivatives which can be obtained from the diols of the type aforementioned.

PART 1 As previously pointed out the monohydric compound C4H9OCH2CH2OCH2CH2OH can be prepared in the customary manner or purchased in the open market. Such compound is then reacted with a suitable reactant, such as glycide, to give a dihydroxy compound. This reaction may be shown thus:

olmo CHzCHzOCHzCHzOH omore-on-cn,

C4H90 CHzCHzO CHzCHeO C3115 In examining the above reaction it is obvious an isomeric mixture could be obtained for a number of reasons. One need not necessarily employ normal butyl alcohol as a starting material although this is the preferred derivative. One could employ one of the usual isomers or a mixture of isomeric butyl alcohols. Stated another way, one could start with any butyl alcohol or any mixture and react the monohydric alcohol so obtained with two moles of ethylene oxide or employ an equivalent reaction. Any isomers or mixtures of isomers could then be reacted with glycide and again the epoxy ring could open, depending on the catalyst used, in either one of two ways. Therefore, when reference is made to the dihydroxy compound obtained for convenience from diethylene glycol monobutyl ether by reaction with glycide or the equivalent it is immaterial which isomer is available or whether a mixture of isomers is used.

As far as forming the dihydroxy compound is concerned other reactions can be employed which do not involve glycide; for example, one can produce ethers of the kind herein employed by use of a glycerol monochlorohydrin, i. e., either alpha or beta glycerol monochlorohydrin. Attention is directed again to the fact that in the previous formula and in the formulas in the claims it would be immaterial whether the free hydroxyl radicals prior to esterification are present as attached to the first and third terminal carbon atoms, or second and third carbon atoms. This is simply an isomeric difference depending on how the epoxy ring is ruptured in the case of glycide, or whether one employs glycerol alpha monochlorohydrin or glycerol beta monochlorohydrin. Other suitable procedure involves the use of epichlorohydrin in a conventional manner. For instance, the oxypropylated compound can be treated with epichlorohydrin and the resultant product treated with caustic soda so as to reform the epoxy ring. The epoxide so obtained can then be treated with water so as to yield a compound having two hydroxyl radicals attached to two of the three terminally adjacent carbon atoms.

Attention is directed to the fact that the use of glycide requires extreme caution. This is particularly true on any scale other than small laboratory or semi-pilot plant operations. Purely from the standpoint of safety in the handling of glycide, attention is directed to the following: (a) If prepared from glycerol monochlorohydrin, this product should be comparatively pure; (2)) the glycide itself should be as pure as possible as the effect of impurities is difficult to evaluate; (c) the glycide should be introduced carefully and precaution should be taken that it reacts as promptly as introduced, 1. e., that no excess of glycide is allowed to accumulate; (d) all necessary precaution should be taken that glycide cannot polymerize per se; (e) due to the high boiling point of glycide one can readily employ a typical separatable glass resin pot as described in U. S. Patent No. 2,499,370, dated March '7, 1950, to De Groote and Keiser, and offered for sale by numerous laboratory supply houses. If such arrangement is used to prepare laboratory-scale duplications, then care should be taken that the heating mantle can be removed rapidly so as to allow for cooling; or better still, through an added opening at the top, the glass resin pot or comparable vessel should be equipped with a stainless steel cooling coil so that the pot can be cooled more rapidly than by mere removal of mantle. If a stainless steel coil is introduced it means that the conventional stirrer of the paddle type is changed into the centrifugal type which causes the fluid or reactants to mix due to swirling action in the center of the pot. Still better is the use of a laboratory autoclave of the kind previously described in this part; but in any event when the initial amount of glycide is added to a suitable reactant, the speed of reaction should be controlled by the usual factors, such as (a) the addition of glycide; (b) the elimination of external heat; and (c) the use of cooling coil so there is no undue rise in temperature. All the foregoing is merely conventional but is included due to the hazard of handling glycide.

Example 1a The equipment used was a glass resin pot of the kind described above. Into this resin pot were charged 5 gram moles of diethylene glycol for another hour.

asse- 'monobutylether. This represented 811" grams.

To this there was added approximately"'1% of sodium methylate equivalent to 8.5 grams. The

temperature of the reaction mass was raised to 120 C;

grams, were added slowly over a period of ap- 5 moles of glycidef'equivalent to 370 proximately 7 hours at a rate of about 50 grams per hour or 'slightlyless at a gram per minute.

Whenever'the' temperature tended to rise past 1 130 'C. the reaction mass was cooled; if the tem 4 perature showed "a tendency to-drop'below 114 C.

to 117 C. the reaction mass was heated. When all the glyci'de had been added'th'e' reaction mass was stirred forapproximately one hourlonger at 135 C., and then was heated to a temperature below *the decomposition point or; "glycide', for

instance, 140 C.', and held at this temperature In this particular reaction there is less hazard than is usuall'y'the case insofar that the amount of glycide added-was com- --p arativelysmall and it was added slowly. Even so, such oxyalkylation could be conductedwith extreme care.

-- rather-than have it react with the glycol-ether.

PART 2 For a number of 'W611 known reason-s equipment, whether laboratory-size, semi-pilot plant size pilotplant size, or large scale'size, isn'ot as a rule designed for a particular alkylene oxide. Invariably and inevitably, however, on particularly in the case of laboratory equipment and pilot plant size the design issuch as to use any of thecustomarily available alkylene oxide, i. e.,

ethylene oxide, propylene oxide, butylene oxide,

glycide, epichlorohydrin, styrene oxide, etc. In

thesubsequent description of' the equipment it becomes obvious that it is adapted for oxyethylation aswell as oxypropylation.

Oxypropylations are conductedunder a wide variety of conditions, not only in regard to presence or absence of catalyst, and the kind of catalyst, but also in regard to the time of reaction, temperature of reaction, speed of reaction-pressure during reaction, etc. For instance, oxyalkylations can be conducted at temperatures up to approximately 200 CJwith pressures in about thesarn'e range up to'about' 200 pounds'per square inch. They can be conducted also at temperatures approximating the boiling point of water or Such low -tem'perature-low reaction rate oxypropylationshave been described very completely able where the compound being subjected to oxyprop-ylation contains one, two or three points of reaction only, such as monohydric alcohols,

* glycols and triols.

"for instance, 1 to? days'of '24 hours-each to complete the reaction'they' areconducted asa rule whether on a laboratory--'scale', pilot' plant scale, or large scale,so as to operate-automatically. The

prior figure of seven *days applies especially tolarge-scale operations. I have usedconventional equipment with two added automaticfeatures; (a) a solenoid controlled value-whichshutsoff the propylene oxide in eventthatthe temperature gets outside a predetermined and -set range, for instance, 95 to 120 CL, and (b) another solenoid valve which shuts off the propylene oxide'tor for that matter ethylene oxide if it is being used) if the pressure gets beyond a predetermined range, such as 25 to pounds} Otherwisythe equipment is substantially the same as is commonly employed for this purpose where thepressure of reaction is highenspeed of reaction is higher, and time of reaction is much shorter. In such instances such automatic controls are not necessarily used.

Thus, in preparing the'various examples I have found it'particularly advantageous to use'laboratory equipment or pilot plant'which is designed to permit continuous oxyalkyla-tion whether it be oxypropylation or oxyethylation; With certain obvious changes the equipment can be used also to permit oxyalkylation involving the use of glycide'where no pressure is involved except'the'vapor pressure of a solvenhif any, which may haveibeen used as a diluent.

As previously pointed outthemethod 'ofusing propylene oxide is the "same as .ethyleneoxide.

This point is emphasized only'ior'the reasonthat the'apparatus is so designedand constructed as to use either oxide.

The oxypropylation procedure employed inithe preparation of the 'oxy'alkylated derivatives has speed oxypropylations require considerable time,

been uniformly the same, particularly inlight of the fact that a continuous automatically-com trolled procedure was employed. In this Tproceduce the autoclave was a conventionalautoclave of stainless steel and'having a, capacity of approximately 15 gallons and a working pressure of one thousand pounds gauge pressure. This pressure obviously is far beyond any requirement as far as propylene oxide goes unless thereis a reaction of explosive violence involved due to accident. The autoclave was equipped with the conventional devices and openings, such as thevariable-speed stirrer operating at speeds from 50 R. P. M. to 500 R. P. M; thermometerwelland thermocouple for mechanical thermometer; .emptying. outlet; pressure gauge, manual vent line;

charge hole for initial reactants; at least onecon- 'nection for introducingthe alkylene oxide such as propylene oxide or ethylene oxide, to the bottom of the autoclave; alon with suitable devices slightly above, as for example to C. Under such circumstances the pressure will be lessthan 30 pounds per square inch unless some specialprocedure is employed as issometimes the case, to wit, keeping an atmosphere of-inert'gas such as nitrogen inth'e vessel during the reaction.

water and further equipped with electrical'heatving devices. essence small-scale replicas of the usual conven- Such autoclaves are, of course, in

tional autoclave used in oxyalkylation procedures. In some instances in exploratory preparations an autoclave having a smaller capacity, for instance, approximately 3 /2 liters in one case and about 1% gallons in another case, was used.

Continuous operation, or substantially continuous operation, was achieved by the use of a separate container to holdthealkylene oxide being employed, particularly propylene oxide. In conjunction with the smaller autoclaves, the container consists essentially of a laboratory bomb having a capacity of about one-half gallon, or somewhat in excess thereof. In some instances a larger bomb was used, to wit, one having a capacity of about one gallon. This bomb was equipped, also, with an inlet for charging, and an eductor tube goin to the bottom of the container so as to permit discharging of alkylene oxide in the liquid phase to the autoclave. A bomb having a capacity of about 60 pounds was used in connection with the 15-gallon autoclave. Other conventional equipment consists, of course, of the rupture disc, pressure gauge, sight feed glass, thermometer connection for nitrogen for pressuring bomb, etc. The bomb was placed on a scale during use. The connections between the bomb and the autoclave were flexible stainless steel hose or tubing 50 that continuous weighings could be made without breaking or making any connections. This applies also to the nitrogen line, which was used to pressure the bomb reservoir. To the extent that it was required, any other usual conventional procedure or addition which provided greater safety was used, of course, such as safety glass protective screens, etc.

Attention is directed again to what has been said previously in regard to automatic controls which shut off the propylene oxide in event temperature of reaction passes out of the predetermined range or if pressure in the autoclave passes out of predetermined range.

With this particular arrangement practically all oxypropylations become uniform in that the reaction temperature was held within a few degrees of any selected point, for instance, if 105 C. was selected as the operating temperature the maximum point would be at the most 110 C. or 112 C., and the lower point would be 95 or possibly 98 C. Similarly, the pressure was held at approximately 30 pounds within a -pound variation one way or the other, but might drop to practically zero, especially where n solvent such as xylene is employed. The speed of reaction was comparatively slow under such conditions as compared with oxyalkylations at 200 C. Numerous reactions were conducted in which the time varied from one day (24 hours) up to three days (72 hours), for completion of the final member of a series. In some instances the reaction may take place in considerably less time, i. e., 24 hours or less, as far as a partial oxypropylation is concerned.

The minimum time recorded was a 4-hour period. Reactions indicated as being complete in four hours or thereabouts may have been complete in a lesser period of time in light of the degree.

automatic equipment used. This applies also to larger autoclaves where the reactions were complete in 9 to 12 hours. In the addition of propylene oxide, in the autoclave equipment as far as possible the valves were set so all the propylene oxide was fed in at a rate so the predetermined amount reacted in the first two-thirds of the selected period; for instance, if the selected period was 3 hours the rate was set so the oxide could be fed in in two hours or less. This meant that if the reaction was interrupted automatically for a period of time for the pressure to drop, or the temperature to drop, the predetermined amount of oxide would still be added in most instances well within the predetermined time period. In one experiment the addition of oxide was made over a comparatively long period, i. e., 10 hours. In such instances, of course, the re- When operating at a comparatively high temperature, for instance, between 150 to 200 C., an unreacted alkylene oxide such as propylene oxide, makes its presence felt in the increase in pressure or the consistency of a higher pressure. However, at a low enough temperature it may happen that the propylene oxide goes in as a liquid. If so, and if it remains unreacted there is, of course, an inherent danger and appropriate steps must be taken to safeguard against this possibility; if need be a sample must be withdrawn and examined for unreacted propylene oxided. One obvious procedure, of course, is to oxypropylate at a modestly higher temperature, for instance, at to C. Unreacted oxide affects determination of the acetyl or hydroxyl value of the hydroxylated compound obtained.

The higher the molecular weight of the compound, i. e., towards the latter stages of reaction, the longer the time required to add a given amount of oxide. One possible explanation is that the molecule, being larger, the opportunity for random reaction is decreased. Inversely, the lower the molecular weight the faster the reaction takes place. For this reason, sometimes at least, increasing the concentration of the catalyst does not appreciably speed up the reaction, particularly when the product subjected to oxyalkylation has a comparatively high molecular weight. However, as has been pointed out previously, operating at a low pressure and a low temperature even in large scale operations as much as a week or ten days time may lapse to obtain some of the higher molecular weight derivatives from monohydric or dihydric materials.

In a number of operations the counterbalance scale or dial scale holding the propylene oxide bomb was so set that when the predetermined amount ,of propylene oxide had passed into the reaction the scale movement through a time operating device was set for either one to two hours so that reaction continued for 1 to 2 /2 hours after the final addition of the last propylene oxide and thereafter the operation was shut down. This particular device is particularly suitable for use on larger equipment than laboratory size autoclaves, to wit, on semi-pilot plant or pilot plant size, as well as on large scale size. This final stirring period is intended to avoid the presence of unreacted oxide.

In this sort of operation, of course, the temperature range was controlled automatically by either use of cooling water, steam, or electrical heat, so as to raise or lower the temperature. The pressuring of the propylene oxide into the reaction vessel was also automatic insofar that the feed stream was set for a slow continuous run which was shut off in case the pressure passed a predetermined point as previously set out. All the points of design, construction, etc., were conventional including the gauges, check valves and entire equipment. As far as I am aware at least two firms, and possibly three, specialize in autoclave equipment such as I have employed in the laboratory, and are prepared to furnish equipment of this same kind. Similarly pilot plant equipment is available. This point is simply made as a precaution in the direction of safety. Oxyalkylations, particularly involving ethylene oxide, glycide, propylene oxide, etc., should not be conducted except in equipment specifically designed for the purpose.

Example 1b Theidihydroxy compound employed was the one previously described which, for purpose of convenience, will be termed the glycerol ether of diethylene glycol monobutyl ether. The autoclave employed was a small autoclave having a capacity of approximately one gallon. This autoclave was equipped with various automatic devices. In some instances the oxypropylations were-run with automatic-controls and in other instances, since the oxypropylation was very short, with manual control. Needless to say, it was immaterial which way the autoclave was handled.-

348 grams of the -dihydroxylated. compound previously described were charged-into the autoclave along-with 35 grams of caustic soda. .It is to be'noted' that the sodium methylate used in the glycide reaction was permitted to remain in the reaction mass. This meant that the concentration of catalyst was slightly higher than indicatedbythe amount of caustic added. The reaction pot was flushed out with nitrogen; the autoclave was sealed and the automatic devices adjusted forinjecting- 1132 grams of propylene oxide in approximately a 4-hour period. The pressure regulator-"wasset'for a maximum of 35 pounds per square inch. This meant that thebulk of the reaction could take place and probably did take place-at a'comparatively lower pressure. This comparatively lower pressure-was the result of the fact that at least in part considerable catalyst was present.- The propylene oxide was added at approximately 300 grams per hour in this instance. The time required to add all the oxide was l hours. More impertant, the selected temperature range was 105 C. (just moderately above the boilingpoint of water). The initial introduction of propylene-oxide was not started until the heating devices-hadraised the, temperature to just a trifleover 100- C.' When the reaction was complete part Of the reactionmasswas withdrawn as a sample'and the remainder subjected to further oxypropylation as described in Example 2b, immediately following.

Example 312 694 grams of thereactionmass identified as Example 21), preceding, were subjected to further.

oxypropylation ,by reactionwith .347 grams of propylene oxide. ,This was introduced without any additional catalyst. The conditionsv of re-;

action, as far as temperature and pressure were concerned, were the same as in ExampleZb; preceding, i. e., maximum temperature of .10" C.

and-maximum pressure of 35 pounds per square inch. -The time required to add the oxide, how-. ever,-Was l0nger,.to Wit, 5 -h0urs, At the completion of the .reactionpart of thereaction mass was-withdrawn and the remainder subjected to the final-oxypropylation step as described in ample 4b immediately following,

Example 4b l 435 grams. of theflreaction mass identified as Example.3b,.preceding, .were subjected to further oxypropylation with 145 grams of propylene oxide. This was reacted without the use of any catalyst. The conditionsof reaction as far as temperature and pressure were, concerned were the same as in Exampleszb and 319 preceding, A

i. e., 110 C.,,maximum temperature and 35.

pounds per square inchmaximumpressure. .The

time requiredto add theoxide wasthe same as in the-first two periods, ,i. e., 4 hours- In the hereto. attached tables it will be noted;

that this series. shows..theoreticalmolecular weights varying from 1,000.to 4,000, and hydroxyl molecular weights varying from alittleless than 800 to a little less than,1900... In another series retical molecularyweight the hydroxyl-molecular weight was, about .2500; andat 7,000; theoretical molecular weight the hydroxyl value was about 2650. I haveesterified .theseparticular oxyproa pylated derivativesas well as the ones specifically described herein.

What has been .said. herein is presented in tabular form .in Table 1- immediately following;

with some added information as to molecular- Example 21) weight and as to solubility-of the reactionprod- 733 am of the reaction mix-ture identified uct in waterbxy en d S TABLE 1' Composition lfiefore Composition at-End M W N0 1.0, Oxide Cata- ,Theo. -H.C.1 Oxide -Oata=- "2 5 lbs. 11mm lbs.-- lbs. lbs. we .1bs. lbs, lbs.

1b 348 35 1,005 348. 1,132 35 770 105 35 4 2b 169, 547 17 2,025 "169 1,280- 17 1,310 "110 35 f 4 30. 79.7 606.2 8.1 3,055 79.8 953.2 8.1 1,595 110 35 5 4b 33.3 seas 3.4' 4,086 33.3. .5433, 3.4 1,870 110 as 4 1 The hydroxylated compound is the glyceroletherof diethyleneglycol monobutyletherr as Examplelhpreceding,were reacted with an addition al fi33,. rams 9f prqpyleneoxide without adding ,any more c atalyst Theconditions of reaction 'were .sllbstanli al th Same a in 4 hours. At the completion of this stage or oxypropylation partof the sample was withdrawn and the remainder subjected-to further oxypropyla-tionas describedin Example 3b immediately following:

Example 1b was-soluble in Waterand' xylene,: but insolublein kerosene; Example2b was.emu1.-,.- sifiable in waterysoluble in xylene,zbut dispersi-y,

ble in kerosene; Example-3b iwasainsoluble in water, soluble in xylene and soluble to disper:-;

sible in kerosene; and Example 4b wasrinsoluble'f in water, but soluble in xylene and kerosenezv The final product, i'. e., at the end of theoxyl-w propylation step, was a somewhat'viscous ambercolored fluid which was water-insoluble. This is characteristic..,oi .all various end products"ob-" ainedin this; series. These. roductsswere, or

ll course, slightly alkaline due to the residual caustic soda employed. This would also be the case if sodium methylate were used as a catalyst.

Speaking of insolubility in water or solubility in kerosene such solubility test can be made simply byshaking small amounts of the materials in a test tube with water, for instance, using 1% to 5% approximately based on the amount of water present.

Needless to say, there is no complete conversion of propylene oxide into the desired hydroxylated compounds. This is indicated by the fact that the theoretical molecular weight based on a statistical average is greater than the molecular weight calculated by usual methods on basis of acetyl or hydroxyl value. Actually, there is no completely satisfactory method for determining molecular weights of these types of compounds with a high degree of accuracy when the molecular weights exceed 2,000. In some instances the acetyl value or hydroxyl value serves as satisfactorily as an index to the molecular weight as any other procedure, subject to the above limitations, and especially in the higher molecular weight range. If any difiiculty is encountered in the manufacture of the esters as described in Part 3 the stoichiometrical amount of acid or acid compound should be taken which corresponds to the indicated acetyl or hydroxyl value. This matter has been discussed in the literature and is a matter of common knowledge and requires no further elaboration. In fact, it is illustrated by some of the examples appearing in the patent previously mentioned.

PART 3 As previously pointed out the present invention is concerned with acidic esters obtained from the oxypropylated derivatives described in Part 1, immediately preceding, and polycarboxy acids, particularly dicarboxy acids such as adipic acid, phthalic acid, or anhydride, succinic acid, diglycollic acid, sebacic acid, azelaic acid, aconitic acid, maleic acid or anhydride, citraconic acid or anhydride, maleic acid or anhydride adducts as obtained by the Diels-Alder reaction from products such as maleic anhydride, and cyclopentadiene. Such acids should be heat stable so they are not decomposed during esterification. They may contain as many as 36 carbon atoms as, for example, the acids obtained by dimerization of unsaturated fatty acids, unsaturated monocarboxy fatty acids, or unsaturated monocarboxy acids having 18 carbon atoms. Reference to the acid in the hereto appended claims obviously includes the anhydrides or any other obvious equivalents. My preference, however, is to use polycarboxy acids having not over 8 carbon atoms.

The production of esters including acid esters (fractional esters) from polycarboxy acids and glycols or other hydroxylated compounds is well known. Needless to say, various compounds may be used such as the low molal ester, the anhydride, the acyl chloride, etc. However, for purpose of economy it is customary to use either the acid or the anhydride. A conventional procedure is employed. On a laboratory scale one can employ a resin pot of the kind described in U. S. Patent No. 2,499,370, dated March '7, 1950, to De Groote & Keiser, and particularly with one more opening to permit the use of a porous spreader if hydrochloric acid gas is to be used as a catalyst. Such device or absorption spreader consists of minute alundum thimbles which are connected to a glass tube. One can add a sulfonic acid such as para-toluene sulfonic acid as a catalyst. There is some objection to this because in some instances there is some evidence that this acid catalyst tends to decompose or rearrange the oxypropylated compounds, and particularly likely to do so if the esterification temperature is too high. In the case of polycarboxy acids such as diglycollic acid, which is strongly acidic there is no need to add any catalyst. The use of hydrochloric gas has one advantage over paratoluene sulfonic acid and that is that at the end of the reaction it can be removed by flushing out with nitrogen, whereas there is no reasonably convenient means available of removing the paratoluene sulfonic acid or other sulfonic acid employed. If hydrochloric acid is employed one need only pass the gas through at an exceedingly slow rate so as to keep the reaction mass acidic. Only a trace of acid need be present. I have employed hydrochloric acid gas or the aqueous acid itself to eliminate the initial basic material. My preference, however, is to use no catalyst whatsoever and to insure complete dryness of the dial as described in the final procedure just preceding Table 2.

The products obtained in Part 2 preceding may contain a basic catalyst. As a general procedure I have added an amount of half-concentrated hydrochloric acid considerably in excess of what is required to neutralize the residual catalyst. The mixture is shaken thoroughly and allowed to stand overnight. It is then filtered and refluxed with the xylene present until the water can be separated in a phase-separating trap. As soon as the product is substantially free from water the distillation stops. This preliminary step can be carried out in the flask to be used for esterifi-cation. If there is any further deposition of sodium chloride during the reflux stage needless to say a second filtration may be required. In any event the neutral or slightly acidic solution of the oxypropylated derivatives described in Part 2 is then diluted further with sufiicient xylene decalin, petroleum solvent, or the like, so that one has obtained approximately a 45% solution. To this solution there is added a polycarboxylated reactant as previously described, such as phthalic anhydride, succinic acid or anhydride, diglycollic acid, etc. The mixture is refluxed until esterification is complete as indicated by elimination of water or drop in carboxyl value. Needless to say, if one produces a halfester from an anhydride such as phthalic anhydride, no water is eliminated. However, if it is obtained from diglycollic acid, for example, water is eliminated. All such procedures are conventional and have been so thoroughly described in the literature that further consideration will be iingited to a few examples and a comprehensive Other procedures for eliminating the basic residual catalyst, if any, can be employed. For example, the oxyalkylation can be conducted in absence of a solvent or the solvent removed after oxypropylation. Such oxypropylation end prod uct can then be acidified with just enough concentrated hydrochloric acid to just neutralize the residual basic catalyst. To this product one can then add a small amount of anhydrous sodium sulfate (suflicient in quantity to take up any water that is present) and then subject the mass to centrifugal force so as to eliminate the sodium sulfate and probably the sodium chloride formed.

The clear somewhat viscous straw-coloredamber liquid so obtained may contain a small amount of sodium sulfate or sodium'chloride but, in any "event, is perfectly acceptable for esterification in the manner described.

It is to be pointed out that the products here described are not polyesters in the sense that there is aplurality of both diol radicals and acid-radicals; the: product is characterized by having only one diol radical.

"I4 After this material is added, refluxing is continued and, of course, is at a high temperature, to wit, about 160 to 170 C. If the carboxy reactant is an anhydride needless to say no water of reaction appears; if the ca-rboxy reactant is an acid, water of reaction should appear and should be eliminated at the above reaction temperature. If it is not eliminated I simply separate out another or 20 cc. of benzene by In' some instances and, in fact, in many in- 10 means of the phase-separating trap and thus "stances I have found that in spite of the deraise the temperature to 180 or 190 C., or even hydration methods employedv above that av mere to 200 0., if need be. My preference is not to trace of'water' still comes through and that this go above 200 C. mere trace of water certainlyinterferes with the The use of such solvent is extremely satisfaca'cetyl or hydroxyl value determination, at least tory provided one does not attempt to remove the when a number ofvconventionalprocedures are solvent subsequently except by vacuum distillaused and may retard esterification, particularly tion and provided there is no objection to a little where there is no sul fonic'acld OI hydrochlollc residue. Actually, when these materials are used acld Present as a catalysif Therefore, have for a purpose such as demulsification the solvent Preferred to use the followmg profzed'urel I h might just as well be allowed to remain. If the employsdlabout rf i g the 2 3 as g gg solvent is to be removed by distillation, and parin P f as: 5 then 9. ture ticularly vacuum distillation, then the high boil- H r uX 1s P ing aromatic petroleum solvent might well be m the glass resm pot using phase'sepamtmg re laced b som more ex ensive solvent su has trap until the benzene carried out all the water y t d d hh present as water of solution or the equivalent. or e l er Ordinarily this refluxing temperature is apt to defimte range bolhng P The be in the neighborhood of 130 to possibly 150 moval of the solvent, of course, is purely a conw all this water or moisture has been ventional procedure and requires no elaboration. removed I also withdraw approximately 20' grams In the appended table solvent which por a little less benzene and then add the rep r in numerous instances, is a mixture of 7 quired amount of the carboxy reactant and also olumes of the aromatic petroleum solvent P about 150 grams of a high boiling aromatic peviously described and 3 volumes of benzene. Reft'roleum solvent. These solvents are sold by Va'rierence to Solvent #7 means the particular petroous oil refineries and, as far as solvent effect act leum solvent previously described in detail. This as if they were almost completely aromatic in was used, or a similar mixture, in the manner c arac yp distillation a in e p previously described. A large number of the ext cular yp I have p y and found y amples indicated were repeated employing decisfac'tory in the following: 10 alin, using this mixture and particularly with the preliminary step of removing all the water. 0 O I. B.P., 142 C. ml., 24 If one does not intend to remove the solvent my 5 ml. 200 C. ml., 244 C. f t th t 1 1 .0 C m1. C. pre erence is 0 use e pe ro eum solventbenzene mixture although obviously any of the 20 216 C. m1" 25210 C. 45 other mixtures, such as decalin and xylene, can 25 ml? 220 0. 7 be employed: 30 m1 5 m1" 4 The data included in the subsequent tables, i. e., 35 m1: 230 C. ml., 270 0. Tables 2 and 3, are self-explanatory, and very 40 1111.123? 9 1 230 3 complete and-it is believed no further elaboration 45 ml., 237 C. ml., 307 C. 50 is necessary:

TABLE 2 V 41 M01 t. f Ex. 325 Agua] gg {fi 1 31 iar 555 7.. $5 3 5.1.1 .1 1 gg, Polycarbmlmm stir Ester Gmpd H. C. H 0. Value lgicltiifa (gm) (2;?)

lb 1, 005 111 770 107'- Diglycolliconic Acid 68.5 25 2,025 55.9 I 85.9 1,310 202 do 41.2 30 3,055 35.7 70.6 1,595 3M 45 4, 086 27.5 60.0 1,870 10 1,005 111 145 770 74 2b 2, 025 55.9 85.9 1,310 59 30 3,055 35.7 70.0 1, 505 5g 2 $832 5- 122- 58 i8 1 25 2, 025 55.9 85.9 1, 310 9 35 3,055 55.7 70.6 1,595 39 r s s 22 10 1,0 20 2,025 55.9 85.9 1, 310 45 3b 3, 055 36. 7 70. 6 1, 595 45 2 as .5 122- r; r 1 25 2, 025 55.9 85.9 1, 310 40 3b 3, 055 36.7 70.6 1,505 40 40 4,086 27.0 50.0 1,870 33 TABLE 3 Ex. No Amt. Esterifica- Time of Water of Acid Solvent Solvent tion Temp, Esterifica- Out Ester (grs.) C. tion (hrs) (00.)

#7-3 256 165 1% 9. 3 #7-3 237 190 8 5. 9 #7-3 234 151 4. 7 #7-3 233 162 7% a. 3 #7-3 260 166 4 N11 #7-3 273 175 4% Nil #7-3 255 160 3% Nil #T-3 268 173 4% Nil #7-3 290 113 5 Nil #7-3 276 156 3%0 Nil #7-3 282 164 4% N1} #7-3 278 177 4% N 1 #7-3 288 158 4% N 11 #7-3 253 161 2% Ni] #7-3 247 150 3 Nil #7-3 300 166 5% N11 #7-3 296 171 4% Nil #7-3 288 168 3% N11 #7-3 240 156 5 Nil #7-3 262 170 4% Ni] The procedure for manufacturing the esters has been illustrated by preceding examples. If for any reason reaction does not take place in a manner that is acceptable, attention should be directed to the following details: (a) Recheck the hydroxyl or acetyl value of the oxypropylated glycerol and use a stoichiometrically equivalent amount of acid; (b) if the reaction does not proceed with reasonable speed either raise the temperatures indicated or else extend the period of time up to 12 or 16 hours if need be; (c) if necessary, use of paratoluene sulfonic acid or some other acid as a catalyst; (at) if the esterification does not produce a clear product a check should be made to see if an inorganic salt such as sodium chloride or sodium sulfate is not precipitating out. Such salt should be eliminated, at least for exploration experimentation, and can be removed by filtering. Everything else being equal as the size of the molecule increases and the reactive hydroxyl radical represents a smaller fraction of the entire molecule and thus more difficulty is involved in obtaining complete esterification.

Even under the most carefully controlled conditions of oxypropylation involving comparatively low temperatures and long time of reaction there ar formed certain compounds whose composition is still obscure. Such side reaction products can contribute a substantial proportion of the final cogeneric reaction mixture. Various suggestions have been made as to the nature of these compounds, such as being cyclic polymers of propylene oxide, dehydration products with the appearance of a vinyl radical, or isomers of propylene oxide or derivatives thereof, i. e., of an aldehyde, ketone, or allyl alcohol. In some instances an attempt to react the stoichiometric amount of a polycarboxy acid with the oxypropylated derivative results in an excess of the carboxylated reactant for the reason that apparently under conditions of reaction less reactive hydroxyl radicals are present then indicated by the hydroxyl value. Under such circumstances there is simply a residue of the carboxylic reactant which can be removed by filtration or, if desired, the esterification procedure can be repeated using an appropriately reduced ratio of carboxylic reactant,

Even the determination of the hydroxyl value by conventional procedure leaves much to be desired due either to the cogeneric materials previously referred to, or for that matter, the presence of any inorganic salts or propylene oxide. Obviously this oxide should be eliminated.

The solvent employed, if any, can be removed from the finished ester by distillation and particularly vacuum distillation. The final products or liquids are generally light straw to light amber in color, and show moderate viscosity. They can be bleached with bleaching clays, filtering chars, and the like. However, for the purpose of demulsification or the like color is not a factor and decolorization is not justified.

In the above instances I have permitted the solvents to remain present in the final reaction mass. In other instances I have followed the same procedure using decalin or a mixture of decalin or benzene in the same manner and ultimately removed all the solvents by vacuum distillation. Appearances of the final products are much the same as the diols before esterification and in some instances were somewhat darker in color and had a reddish cast and perhaps somewhat more viscous.

PART 4 Previous reference has been made to the fact that diols such as polypropyleneglycol of approximately 2,000 molecular weight, for example, have been esterified with dicarboxy acids and employed as demulsifying agents. On first examination the difierence between the herein described products and such comparable products appears to be rather insignificant. In fact, the difference is such that it fails to explain the fact that compound of the kind herein described may be, and frequently are, 10%, 15% or 20% better on a quantitative basis than the simpler compound previously described, and demulsify faster and give cleaner oil in many instances. The method of making such comparative tests has been described in a booklet entitled Treating Oil Field Emulsion, used in the Vocational Training Courses, Petroleum Industry Series, of the American Petroleum Institute.

The difference, of course, does not reside in the carboxy acid but in the diol. Momentarily an eficrt will be made to emphasize certain things in regard to the structure of a polypropylene glycol, such as polyp py glycol O a 2000 molecular weight. Propylene glycol has a primary alcohol radical and a secondary alcohol radical. In this sense the building unit which forms polypropylene glycols is not symmetrical. Obviously, then, polypropylene glycols can be obtained, at least theoretically, in which two sec ondary alcohol groups are united or a secondary alcohol group is united to a primary alcohol group, etherization being involved, of course, in each instance.

Usually no effort is made to difierentiate between oxypropylation taking place, for example, as the primary alcohol unit radical or the secondary alcohol radical. Actually, when such products are obtained, such as a high molal polypropylene glycol or the products obtained in the manner herein described one does not obtain a single derivative such as HO(RO)nH in which n has one and only one value, for instance, 14, 15' or 16, or the like. Rather, one obtains a cogeneric mixture of closely related or touching homologues. These materials invariably have high molecular weights and cannot be separated from one another by any known procedure without decomposition. The properties of such mixture represent the contribution of the various individual members of the mixture. On a statistical basis, of course, it can be appropriately specified. For practical purposes one need only consider the oxypropylation of a monohydric alcohol because in essence this is substantially the mechanism involved. Even in such instances where one is concerned with a monohydric reactant one cannot draw a single formula and say that by following such procedure one can readily obtain 80% or 90% or 100% of such compound. However, in the case of at least monohydric initial reactants one can readily draw the formulas of a large number of compounds which appear in some of the probable mixtures or can be prepared as components and mixtures which are manufactured conventionally.

Simply by way of illustration reference is made to the copending application of De 'Groote, Wirtel and Pettingill, Serial No. 109,791, filed August 11, 1949 (now Patent 2,549,434, granted April 17, 1951).

However, momentarily referring again to a monohydric initial reactant it is obvious that if one selects any such simple hydroxylated compound and subjects such compound to oxyalkylation, such as oxyethylation, or ioxyp'ropylation, it becomes obvious that one is really producing a polymer of the alkylene oxides except for the terminal group. This is particularly true where the amount of oxide added is comparatively large, for instance, 10, 20, 30, 40, or 50 units. If such compound is subjected to oxyethylation so as to introduce units of ethylene oxide, it is Well 4 known that one does not obtain a single constituent which, for the sake of convenience, may be indicated as RO(C2H4O)30OH. Instead, one obtains a cogeneric mixture of closely related homologues, in which the formula may be shown as the following; RO(C2H40)52H, wherein n, as far as the statistical average goes, is 30, but the individual members present in significant amount may vary from instances where a has a value of 25, and perhaps less, to a point where it may represent or more. Such mixture is, as stated, a cogeneric closely related series of touching homologous compounds. Considerable investigation has been made in regard to the distribution curves for linear polymers. Attention is directed to the article entitled Fundamental Principles of Condensation Polymerization, by Flory, which appeared in Chemical Reviews, Volume 39, No. 1, page 137.

Unfortunately, as has been pointed out by Flory and other investigators, there is no satisfactory method, based on either experimental or mathematical examination, of indicating the exact pro portion of the various members of touching homologous series which appear in cogeneric con densation products of the kind described. This means that from the practical standpoint, i. e., the ability to describe how to make the product under consideration and how to repeat such production time after time without difiiculty, it is necessary to resort to some other method of description, or else consider the value of n, in formulas such as those which have appeared previously and which appear in the claims, as representing both individual constituents in which n has a single definite value, and also with the understanding that n represents the average statistical value based on the assumption of completeness of reaction.

This may be illustrated as follows: Assume that in any particular example the molal ratio of the propylene oxide to the diol is 15 to 1. Actually, one obtains products in which n probably varies from 10 to 20, perhaps even further. The average value, however, is- 15, assuming, as previously 18 stated, that the reaction is complete. The product described by the formula is best described also in terms of method of manufacture.

However, in the instant situation it becomes obvious that if an ordinary high molal propyl eneglycol is compared to strings of white beads of various lengths, the diols herein empldyed as intermediates are characterized by the presence of a black bead, 1. a, a radical which corresponds to the glycerol ether of diethylene glycol mono= butyl ether as previously described, 1. e., the radical Furthermore, it becomes obvious now that one has a nonsymmetrical radical in the majority of cases for reason that in the cogeneric mixture going back to the original formula n and n are usually not equal. For instance, if one introduces 15 moles of propylene oxide, n and n could not be equal, insofar that the nearest approach to equality is where the value of n is 7 and n is 8. However, even in the case of an even number such as 20, 30, 40 or 50, it is also obvious that n and n will not be equal in light of what has been said previously. Both sides of the molecule are not going to grow with equal rapidity, i. e., to the same size. Thus the diol herein employed is differentiated from polypropylene diol 2000, for example, in that (a) it carries a hereto unit, i. e., a unit other thana propylene glycol or propylene oxide unit, (b) such unit is off center, and (c) that unit, of course, must have some efiect in the range with which the linear molecules can be drawn together by hydrogen binding or van der Waals forces, or whatever else may be involved.

What has been said previously can be emphasized in the following manner. It has been pointed out previously that in the last formula immediately preceding, n or it could be zero. Under the conditions of manufacture as described in Part 2 it is extremely unlikely that n is ever zero. However, such compounds can be prepared readily with comparatively little difficulty by resorting to a blocking effect or reaction. For instance, if the diol is esterified with a low molal acid such as acetic acid mole for mole and such product subjected to oxyalkylation using a catalyst, such as sodium methylate and guarding against the presence of any water, it becomes evident that all the propylene oxide introduced, for instance 15 to moles, necessarily must enter at one side only. If such product is then saponified so as to decompose the acetic acid ester and then acidifled so as to liberate the Water-soluble acetic acid and the water-insoluble diol a separation can be made and such diol then subjected to eSterification as described in Part 2, preceding. Such esters, of course, actually represent products where either 'n or n is zero. Also intermediate proc'e-' dures can be employed, i. e., following the same esterification step after partial oxypropylation. For instance, one might oxypropylate with onehalf the ultimate amount of propylene oxide to .be used and then stop the reaction. One could then convert this partial oxypropylated intermediate into an ester byreaction of one mole of acetic acid with one mole of a diol. This ester 1% could then be oxypropylated with all the remaining propylene oxide. The final product so obtained could be saponified and acidified so as to eliminate the water-soluble acetic acid and free the obviously unsymmetrical diol which, incidentally, should also be kerosene-soluble.

From a practical standpoint I have found no advantage in going to this extra step but it does emphasize the difference in structure between the herein described diols employed as intermeiates and high molal polypropylene glycol, such as polypropylene glycol 2000.

The most significant fact in this connection the following. The claims hereto attached are directed to a very specific compound, i. e., one derived by the oxypropylation of the glycerol ether of ethylene glycol monobutyl ether. In addition to this glycol ether there are available a large number of other glycol ethers as, for example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol ethylbutyl ether, ethylene glycol monobutyl ether, ethylene glycol monobenzyl ether, diethylene glycol monomethyl ether, and diethylene glycol monocthyl ether.

I have taken each and every one of these glycol ethers and, as a matter of fact, a large number of others, subjected them to reaction with giycide and then oxypropylated the compounds and esterified them in the manner described in the instant application, I have tested all these products for demulsification and at least to date I have not found another analogous compound equally effective for demulsification and also for certain other applications in which surface activity is involved. At the moment, based on this knowledge, this particular compound appears unique for reasons not understood.

PART 5 Conventional demulsifying agents employed in the treatment of oil field emulsions are used as such, or after dilution with any suitable solvent, such as water, petroleum hydrocarbons, such as benzene, toluene, xylene, tar acid oil, cresol, anthracene oil, etc. Alcohols, particularly aliphatic alcohols, such as methyl alcohol, ethyl alcohol, denatured alcohol, propyl alcohol, butyl alcohol, hexyl alcohol, octyl alcohol, etc., may be employed as diluents. Miscellaneous solvents such as pine oil, carbon tetrachloride, sulfur dioxide extract obtained in the refining of petroleum, etc., may be employed as diluents. Similarly, the material or materials employed as the demulsifying agent of my process may be admixed with one or more of the solvents customarily used in connection with conventional demulsifying agents. Moreover, said material or materials may be used alone or in admixture with other suitable well-known classes of demulsifying agents.

It is well known that conventional demulsifying agents may be used in a water-soluble form, or in an oil-soluble form, or in a form exhibiting both oiland water-solubility. Sometimes they may be used in a form which exhibits relatively limited oil-solubility. However, since such reagents are frequently used in a ratio of 1 to 10,000 or 1 to 20,000, or 1 to 30,000, or even 1 to 40,000, or 1 to 50,000 as in desalting practice, such an apparent insolubility in oil and Water is not significant because said reagents undoubtedly have solubility within such concentrations. This same fact is true in regard to the material or materials employed as the demulsifying agent of my process.

In practicing my process for resolving petroleum emulsions of the water-in-oil type, a treating agent or demulsifying agent of the hind above described is brought into contact with or caused to act upon the emulsion to be treated, in any of the various apparatus now generally used to resolve or break petroleum emulsions with a chemical reagent, the above procedure being used alone or in combination with other demulsifying procedure, such as the electrical dehydration process.

One type of procedure is to accumulate a volume of emulsified oil in a tank and conduct a batch treatment type of demulsiiication procedure to recover clean oil. In this procedure the emulsion is admixed with the demulsifier, for example by agitating the tank of emulsion and slowly dripping deinulsifier into the emulsion. In some cases mixing is achieved by heating the emulsion while dripping in the demulsifier, depending upon convection currents in the emulsion to produce satisfactory admixture. In a third modification of this type of treatment, a circulating pump withdraws emulsion from, c. g., the bottom of the tank, and reintroduces it into the top of the tank, the demulsifier being added, for example, at the suction side of said circulating pump.

In a second type of treating procedure, the demulsifier is introduced into the well fluids at the well-head or at some point between the wellhead and the final oil storage tank, by means of an adjustable proportioning mechanism or proportioning pump. Ordinarily the flow of fluids through the subsequent lines and fittings suffices to produce the desired degree of mixing of demulsifier and emulsion, although in some instances additional mixing devices may be introduced into the flow system. In this general procedure, the system may include various mechanical devices for withdrawing free water, separating entrained water, or accomplishing quiescent settling of the chemicalized emulsion. Heating devices may likewise be incorporated in any of the treating procedures described herein.

A third type of application (down-the-hole) of demulsifier to emulsion is to introduce the demulsifier either periodically or continuously in diluted or undiluted form into the well and to allow it to come to the surface with the well fluids, and then to flow the chemicalized emulsion through any desirable surface equipment, such as employed in the other treating procedures. This particular type of application is decidedly useful when the demulsifier is used in connection with acidification of calcareous oilbearing strata, especially if suspended in or dissolved in the acid employed for acidification.

In all cases, it will be apparent from the foregoing description, the broad process consists simply in introducing a relatively small propor-- tion of demulsifier into a relatively large proportion of emulsion, admixing the chemical and emulsion either through natural flow or through special apparatus, with or without the application of heat, and allowing the mixture to stand quiescent until the undesirable water content of the emulsion separates and settles from the mass.

The following is a typical installation.

A reservoir to hold the demulsifier of the kind described (diluted or undiluted) is placed at the Well-head where the effluent liquids leave the well. This reservoir or container, which may vary from 5 gallons to gallons for convenience,

is connected to a proportioning pump which injects the demulsifier drop-wise into the fluids leaving the well. Such chemicalized fluids pass through the fiowline into a settling tank. The settling tank consists of a tank of any convenient size, for instance, one which will hold amounts of fiuid produced in 4 to 24 hours (500 barrels to 2000 barrels capacity), and in which there is a perpendicular conduit from the top of the tank to almost the very bottom so as to perm-it the incoming fluids to pass from the top of the settling tank to the bottom, so that such incoming fluids do not disturb Stratification which takes place during the course of demul'sifica'tion. The settling tank has two outlets, one being below the water level to drain off the Water resulting from demulsification or accompanying the emulsion as free water, the other being an oil outlet at the top to permit the passage of dehydrated oil to a second tank, being a storage tank, which holds pipeline or dehydrated oil. If desired, the conduit or pipe which serves to carry the fluids from the well to the settling tank may include a section of pipe with baffles to serve as a mixer, to insure thorough distribution of the demulsifier throughout the fluids, or 'a heater for raising the temperature of the fluids to some convenient temperature, for instance, 120 to 160 F., or both heater and mixer.

Demulsification procedure is started by simply setting the pump so as to feed a comparatively large ratio of demulsifier, for instance, 1:5,000. As soon as a complete break or satisfactory demulsification is obtained, the pump is regulated until experience shows that the amount of demulsifier being added is just sufficient to produce clean or dehydrated oil. The amount being fed at such stage is usually l:10,000, 1115,000, l:20,000, or the like.

In many instances the oxyalkylated products herein specified as demulsifiers can be conveniently used without dilution. However, as previously noted, they may be diluted as desired with any suitable solvent. For instance, by mixing 75 parts by weight of the product of Example 40 with 15 parts by weight of xylene and parts by weight of isopropyl alcohol, an excellent demulsifier is obtained. Selection of the solvent will vary, depending upon the solubility characteristics of the oxyalkylated product, and of course will be dictated in part by economic considerations, 1. e., cost.

As noted above, the products herein described may be used not only in diluted form, but also may be used admixed with some other chemical demulsifier. A mixture which illustrates such combination is the following:

Oxyalkylated derivative, for example, the product of Example 40, 20%

A cyclohexylamine salt of a polypropylated naphthalene monosulfonic acid, 24%;

An ammonium salt of a polypropylated naph thalene mono-sulfonic acid, 24%

A sodium salt of oil-soluble mahogany petroleum sulfonic acid, 12%;

A high-boiling aromatic petroleum solvent, 15%;

Isopropyl alcohol, 5

The above proportions are all weight percents.

PART 6 As pointed out previously the final product obtained is a fractional ester having free carboxyl radicals. Such product can be used as an intermediate for conversion into other derivatives which are effective for various purpo es, such as the breaking of petroleum emulsions of the kind herein described. For instance, such product can be neutralized with an amine so as to increase its water-solubility such as triethanolamine, tripropanolamine, cxyethylated triethanolamine, etc. Similarly, such product can be neutralized with amine which tends to reduce the watersolubility such as cyclohexylamine, benzylamine, decylamine, tetradecylamine, octadecylamine, etc. Furthermore, the residual carboxyl radicals can be esterified with alcohol, such as low molal alcohols, methyl, ethyl, propyl, butyl, etc., and also high molal alcohols, such as octyl, decyl, cyclohexanol, benzyl alcohol, octadecyl alcohol, etc. Such products are also valuable for a variety of purposes due to their modified solubility. This is particularly true where surface-active materials are of value and especially in demulsification of water-in-oil emulsions.

Having thus described my invention what I claim as new and desire to secure by Letters Patent, is:

1. A process for breaking petroleum emulsions of the water-in-oil type characterized by-subjecting the emulsion to the action of a demulsifier including hydrophile synthetic products; said hydrophile synthetic products being characterized by the following formula:

in which R. is the radical of a glycerol ether of diethylene glycol monobutyl ether; n and n are numerals with the proviso that n and n e'qual a sum varying from 15 to 80, and n" is a whole number not over 2, and R is the radical of the polybasic acid coon ooonw in which n" has its previous significance, and with the further proviso that the parent dihydroxylated compound prior to esterification be water-insoluble.

2. A process for breaking petroleum emulsions of the water-in-oil type characterized by subjecting the emulsion to the action of a demulsifier including hydrophile synthetic products; said hydrophile synthetic products being characterized by the following formula:

in which R is the radical of a glycerol ether of diethylene glycol monobutyl ether, in which the butyl radical is that of normal butyl alcohol; n and n are numerals with the proviso that n and n equal a sum varying from 15 to 80, and n is a whole number not over 2, and R is the radical of the polybasic acid in which n" has its previous significance, and with the further proviso that the parent dihydroxylated compound prior to esterification be water-insoluble.

3. A process for breaking petroleum emulsions of the water-in-oil type characterized by subjecting the emulsion to the action of a demulsifier including hydrophile synthetic products; said hy- 23 drophile synthetic products being characterized by the following formula:

I? if (HOOC)n"RC(OCsHe)"ORO(CaHsO)n'CR(COOH),.-

in which R is the radical of a glycerol ether of diethylene glycol monobutyl ether, in which the butyl radical is that of normal butyl alcohol; 11 and n are numerals with the proviso that 'n and 1 equal a sum varying from to 80, and n" is a whole number not over 2, and R is the radical of the polybasic acid coon in which R is the radical of a glycerol ether of diethylene glycol monobutyl ether, in which the butyl radical is that of normal butyl alcohol; n and n are numerals with the proviso that n and n equal a sum varying from 15 to 80, and n is a whole number not over 2, and R is the radical of the polybasic acid COOH (COOLED in which n" has its previous significance, said polycarboxy acid having not over 8 carbon atoms; and with the further proviso that the parent dihydroxylated compound prior to esterification be water-insoluble and at least kerosene-dispersible.

5. A process for breaking petroleum emulsions of the water-in-oil type characterized by subjecting the emulsion to the action of a demulsifier including hydrophile synthetic products; said hydrophile synthetic products being characterized by the following formula in which R is the radical of a glycerol ether of diethylene glycol monobutyl ether, in which the butyl radical is that of normal butyl alcohol; n and n are numerals with the proviso that n and n equal a sum varying from 15 to 80, and R is the radical of the dicarboxy acid COOH said dicarboxy acid having not over 8 carbon atoms; and with the further proviso that the parent dihydroxylated compound prior to esterification be water-insoluble and at least kerosene-dispersible.

6. The process of claim 5 wherein the dicarboxy acid is phthalic acid.

7. The process of claim 5 wherein the dicarboxy acid is maleic acid.

8. The process of claim 5 wherein the dicarboxy acid is succinic acid.

9. The process of claim 5 wherein the olicarboxy acid is citraconic acid.

10. The process of claim 5 wherein the dicarboxy acid is diglycollic acid.

MELVIN DE GROOTE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,552,528 De GI'OOte May 15, 1951 2,562,878 Blair Aug. 7, 1951 

1. A PROCESS FOR BREAKING PETROLEUM EMULSIONS OF THE WATER-IN-OIL TYPE CHARACTERIZED BY SUBJECTING THE EMULSION TO THE ACTION OF A DEMULSIFIER INCLUDING HYDROPHILE SYNTHETIC PRODUCTS; SAID HYDROPHILE SYNTHETIC PRODUCTS BEING CHARACTERIZED BY THE FOLLOWING FORMULA: 